Recently I switched to mojarra from myfaces and noticed that primefaces datatable checkbox multiple row selection is not working.
I have tried the exact sample program available at http://www.primefaces.org/showcase/ui/datatableRowSelectionRadioCheckbox.jsf
With myfaces both single and multiple selection are working ,but with mojarra multiple selection is not working(selectedCars.length is 0 in setSelectedCars method)
I have tried with mojarra 2.0.3 and mojarra 2.1.0 with primefaces 2.2.1
Adding 'f:view contentType="text/html"' solved the problem.
Read this in http://www.primefaces.org/faq.html